1. Field of the Invention
The present invention relates generally to a fiber optic cable assembly having a distribution cable and one or more tethers optically connected to optical fibers in the distribution cable. An attachment structure is provided for maintaining the tether to the distribution cable such that the tether has a freedom of movement and is able to move relative to the distribution cable to prevent damage to the tether as the assembly is subjected to forces. In one embodiment, the attachment structure permitting movement of the tether in relation to the distribution cable, for example, the movement being a generally translational movement, a lateral movement, and limited rotation of the tether. The attachment structure may also protect a connectorized end of the tether.
2. Technical Background
Fiber optic cable assemblies are being developed to deliver services to subscribers for voice, video, and data services. In this regard, both indoor and outdoor cable assemblies are being developed in which a fiber optic distribution cable is accessed at a preterminated location along its length to access the optical fibers within. Pre-selected optical fibers are preterminated and spliced or otherwise optically connected to optical fibers of a drop or tether cable. The distribution cable in a buried, aerial, or duct application is used to provide a trunk or main run, while a tether cable may be used to provide a branch off of the main trunk. For example, the tether cable may provide a branch that supplies services to a floor of a multi-dwelling unit, or a branch to an apartment building. Tethers may have any desired length. The tethers are typically attached to the distribution cable at a network access point and lashed to the cable along their length so that they may be wound on a reel along with the distribution cable and readily installed. The lashing is done in a way that inhibits or even prevents movement. A tether may terminate in, for example, splice-ready optical fibers, connectorized fibers, or an optical connection terminal.
Because of significant forces applied to cable assemblies during installation or removal, for example, bending, torsion, and tensile forces, the cable assemblies can suffer damage as the assemblies are pulled forward and backward. In particular, attached tethers are especially vulnerable to such forces and are often unintentionally ripped or disengaged from the distribution cable to which they are attached. Further, the location of strength elements within the distribution cable, such as glass reinforced plastic or other polymer-based elements, creates a preferential bend, such that when the cable assembly is coiled up, forces are applied which tend to compel the tether to move relative to the distribution cable along a linearly constrained path. This causes problems when trying to firmly secure the tether to the distribution cable and leads to the tether lashings being fractured or otherwise ripped or torn apart, so that the tether is subject to damage. Moreover, any connector(s) attached to the end of the tether is subject to damage during the coiling, installation, or removal procedures. It would be desirable to provide a cable assembly structure that maintains the tether to the distribution cable while allowing translation between the tether and the distribution cable to prevent tether damage during installation as the cable assembly is subject to forces, and providing protection for optical connector(s) attached to the tethers.